Waterfalls grace the upper reaches of the San Diego River, where only the most competent hikers tread.

A trip down the San Diego River canyon during the rainy season is a true adventure. (Mind you, we are not referring to the river at its lower Mission Valley segment, or even at Mission Gorge; rather, this section is way up in the mountains toward Julian.) Runoff from winter storms fills the rocky riverbed with a silvery band of water. Green grass, new leaves, and wildflowers (appearing by February or March) brighten the banks as well as the slopes. In several places along the way the stream cascades over rock precipices, including one with a drop of 100 hundred feet.

Bedrock morteros (grinding holes) along the river, especially near groves of oaks, attest to frequent use of the canyon by Native Americans for hundreds of years or more. Contemporary human usage pales by comparison; only an occasional hiker, backpacker, or hunter penetrates these canyon depths today.

Sturdy boots and a patient, cautious attitude are essential for exploring the canyon. This is a trek suitable only for those adept at moving through steep, rough terrain, and comfortable with occasional scrambling bordering on technical rock climbing. Get an early start if you are planning anything other than a brief, cursory look at the canyon. Keep in mind, too, that any substantially wet, winter-season storm could temporarily swell the usually indolent river flow to a dangerous level.

You may park at Inaja Picnic Area in the Cleveland National Forest, where you must post a National Forest Adventure Pass on your car for the privilege of parking. Start off by descending a precipitous slope south of the restrooms into the canyon's oak-shaded floor, a short distance below. Turn down-canyon, and at 0.5 mile arrive at the first falls, a set of two, each about 50 feet high. To get by, you'll probably need to traverse through brush and over tilted rock slabs on the right (west) side. If you don't like this dicey maneuver, go no further and turn back. You will encounter nothing but long stretches of boulder hopping, and occasional rock climbing ahead. The 2003 Cedar Fire incinerated the thick brush that was starting to make passages down the river canyon almost impossible. Now, however, that same vegetation is growing back.

After a total of 3.2 miles and perhaps 4 or more arduous hours, you'll come upon the lip of a 100-foot waterfall (elevation 1950 feet) -- the highest falls on the San Diego River. The water tumbles over a rock face and collects in a shallow pool perhaps 60 feet across. This destination is about as far as it is prudent to go in a full day. Remember that the hike back is all uphill and will almost certainly take a lot longer than did the hike down.

This article contains information about a publicly owned recreation or wilderness area. Trails and pathways are not necessarily marked. Conditions can change rapidly. Hikers should be properly equipped and have safety and navigational skills. The Reader and Jerry Schad assume no responsibility for any adverse experience.